The 4-20 mA Current Loop
The I/O capabilities built into most microcontrollers make it easy to measure the analog world. Say you want to build a data logger for temperature. All you need to do is get some kind of sensor that has a linear voltage output that represents the temperature range you need to monitor — zero to five volts representing 0° to 100°C, perhaps. Hook the sensor up to and analog input, whip up a little code, and you’re done. Easy stuff.
Now put a twist on it: you need to mount the sensor far from the microcontroller. The longer your wires, the …read more
Paul Horowitz and the Search for Extra Terrestrial Intelligence
I recently had the opportunity to attend a lecture by Harvard Professor Paul Horowitz. It’s a name you likely recognize. He is best known for his iconic book the Art of Electronics which is often referred to not by its name but by the last names of the authors: “Horowitz and Hill”.
Beyond that, what do you know about Paul Horowitz? Paul is an electrical engineer and physicist and Paul has spent much of his storied career learning and practicing electronics for the purpose of finding intelligent extra terrestrial life. …read more
I am an Iconoscope
We’d never seen an iconoscope before. And that’s reason enough to watch the quirky Japanese, first-person video of a retired broadcast engineer’s loving restoration. (Embedded below.)
Quick iconoscope primer. It was the first video camera tube, invented in the mid-20s, and used from the mid-30s to mid-40s. It worked by charging up a plate with an array of photo-sensitive capacitors, taking an exposure by allowing the capacitors to discharge according to the light hitting them, and then reading out the values with another electron scanning beam.
The video chronicles [Ozaki Yoshio]’s epic rebuild in what looks like the most amazingly …read more
The documentation is a bit sparse …read more
Ask Hackaday: Selling Yourself as a Hacker
While there are plenty of hackers that hack just for the love of it, it’s no secret that many of us are looking to hit it big someday. Tales of the businesses like HP and Apple that started in someone’s garage inevitably lead to musings like, “Hey, I’ve got a garage!” and grand plans to turn that special idea into the Next Big Thing™. Many will try, most will fail for one reason or another, but hope springs eternal, and each new widget seems to start the entrepreneurial cycle again.
But for as much pressure as we may feel …read more